1. Technical Field of the Invention
The present invention relates to an exchange such as PBX (Private Branch Exchange) composed to allow to conveniently execute emergency call such as Enhanced 911 call.
2. Related Art
FIG. 17 shows a system for emergency call composed using PBX 10. In this system, an E911 unit 4 to be connected to a CAMA (Centralized Automatic Message Accounting) line 7, one of corresponding lines for realizing an Enhanced 911 call (called E911 call, hereinafter), is connected to the outside of the PBX 10, to be used as adapter of the PBX 10 and the CAMA line 7.
Here, an E911 call is an emergency call (911 call) of which function is enhanced. According to this E911 call, it is adopted an approach wherein caller ID information or the like are sent to a station upon originating of an emergency call and the station obtains the caller location information based on this information, apprising facilities for emergency, where fire-fighting or similar emergency team is watching, of this information. As a consequence, the emergency team can arrive at the origin of call without fail.
The E911 unit 4 is an interface for transmitting the caller ID or others via the CAMA line 7 and is provided with a procedure for sending the caller ID (MF tone signal) to the station via T1 (digital) or TIE (bus) line or the like.
To the PBX 10 of FIG. 17 are connected an degital key telephone 2 and a standard telephone set 3 and, on the other hand, it is connected to the E911 unit 4 via a general purpose bus 6 such as TIE line, and is connected to the public network (PSTN) 5 via respective lines. The 911 unit 4 is connected to a 911 Tandem Office 8 via the CAMA line 7.
Moreover, the PBX 10 comprises a control section 11 including a time switch 111, a transmitting and receiving interface 12, a digital line interface 13, a DKT (digital key telephone) interface 14, a standard telephone set interface 15, and a station line interface 16, the control section 11 and respective interfaces 12 to 16 being connected by a PCM highway (speech highway) L1 and a data highway L2.
In addition, the E911 unit 4 is composed as shown in FIG. 18. The E911 unit 4 includes a receipt detector 61 for detecting a call-in from the PBX 10, a dial detector 62 for detecting dial data of DTMF signal originated from the PBX 10, a CPU 63 for supervising and controlling operations of the E911 unit 4 and a CAMA line interface 64 to be connected to the CAMA LINE 7. Plural elements other than the CPU 63 are provided with so as to allow simultaneously a plurality of E911 calls from the PBX 10.
Upon arrival of a call-in signal from the PBX 10, the call-in detector 61 detects it and inform the CPU 63 of receipt detection. Now, the CPU 64 waits that an extension number allocated to an extension telephone terminal sent by the PBX 10 be detected by the dial detector 62. This extension number serves as an ANI (Automatic Numbering Identification) signal corresponding to the caller location information. Upon the detection of the transmitted extension number by the dial detector 62, the CAMA line interface 64 closes the CAMA line 7, sends a connect signal to 911 Tandem Office 8 and, moreover, transmits the extension number (ANI) detected. Owing to this, the 911 Tandem Office 8 obtains the caller location information based on this information and apprises facilities for emergency, where fire-fighting or similar emergency team is attending, of this information. At the same time, the PBX 10 will be connected to the CAMA line 7 via the call-in detector 61 and the CAMA line interface 64, enabling the emergency call.
The emergency call operation by the PBX 10 mentioned above will be described in reference to the flow chart of FIG. 19. Upon a dial input (S501) via the DKT interface 14 from the digital key telephone 2, the control section 11 of the PBX 10 determines whether it is an E911 call or not (S502). In other words, if xe2x80x9c911xe2x80x9d is dial-input, it constitutes an E911 call, originating the step S503 to capture a trunk leading to the E911 unit 4 through the digital line interface 13 (S503).
At that time, the control section 11 determines whether there is or not a vacancy in the CAMA line interface 64 inside the E911 unit 4 (S504), and if there exists the vacancy, calls in the E911 unit 4 and then change an ANI signal including ID information of the digital key telephone 2 into a DTMF signal and transmits the DTMF signal to the E911 unit 4 via the general purpose bus 6 for performing an E991 call (S505).
Here, the ANI corresponding to the caller location information is registered in the control section 11 of the PBX 10 in response to the extension telephone. The E911 unit 4 receives the ANI signal transmitted from the PBX 10, converts it into MF tone signal and sends it to the 911 Tandem Office 8 through the CAMA line 7. The 911 Tandem Office 8 has the composition for retrieving the database of caller location information ALI (Automatic Location Information) corresponding to the ANI signal and for delivering, from this information, an emergency message communication to a firehouse or the like nearest to the caller. Therefore, it can advantageously transmit surely and rapidly where an emergency message has been generated, without calling a PSAP (Public Safety Answering Point).
In the step S502 of FIG. 19, if it is determined that it is not an E911 call, a call processing using the public network (PSTN) 5 shall be performed by the station interface 16 (S506). On the other hand, in the step S504, if there is no vacancy in the CAMA circuit interface 64, an ordinary emergency call processing to call the nearest firehouse or the like using the public network 5 by the station line interface 16 shall be performed (S507).
As mentioned above, when an E911 call is to be made from the PBX 10 using the E911 unit 4, if the CAMA circuit interface 64 in the E911 unit 4 is occupied, the E911 call can not be made, even if there exists an interface (such as transmitting and receiving interface 12) connected to an E911 call corresponding line by MF signal, because the PBX 10 is lacking for MF signal source though it includes a mechanism for transmitting a DTMF signal. To resolve this inconvenience, it has been necessary to dispose an MF signal source in the PBX 10.
FIG. 20 shows a block diagram of the control section 11 provided with a MF signal source. In this example, an MF tone generation circuit 114 for generating more various MF tones than the dial key corresponding DTMF tone is added to the control section 11 in the PBX 10, in addition to a DTMF tone generation circuit 113 for generating dial key corresponding DTMF tone, for increasing the kind of tones. Here, the tone output time range in respect to a PCM highway L1 being limited by a main CPU 112, the main CPU 112 will be loaded heavily.
For example, an MF tone output from the MF tone generation circuit 114 will be arranged to the channel 0 (CH0) to the channel 31 (CH31) as shown in (21A) of FIG. 21, to be transmitted as input stream for MF tone. There, the time switch 111 outputs to the channel 2 and thereafter in the PCM highway L1 having channel 0 (CH0) to channel 31 (CH31), and this stream is shown by (21B) of FIG. 21. Here, the digit output time interval of MF tone is defined to 60 mSxc2x10.5 mS, so it becomes difficult to control the time interval when the main CPU 112 is loaded heavily.
Moreover, the PBX 10 will includes a MF signal source in addition to the MF signal source provided in the E911 unit 4; as a consequence, it will be redundant to have double MF signal source in a system. On the other hand, as the E911 unit 4 is connected to the PBX 10 outside, when E911 call can not originated through the E911 unit 4, it is necessary to verify whether the fault is due to the E911 unit 4 to network side, or to the general purpose bus 6, or to the PBX 10, increasing the time and work for restoration. Technology concerning such emergency call is disclosed in U.S. Pat. No. 5,235,630 or Japanese Patent Application 6-168318 (Publication No. 8-32703).
The present invention has been made to solve problems mentioned above and intends to provide a telephone exchange apparatus capable of conveniently executing an emergency call to a line corresponding to the Enhanced 911 call. Moreover, it avoids the redundancy of providing double MF signal source. Additionally, it always maintains the digit output time interval of MF tone signal with a high accuracy. When E911 call is disabled, it facilitates to localize the cause. Moreover, it selects automatically a line corresponding to the emergency call to perform an emergency call. On the other hand, it transmits automatically the identification information of an extension telephone terminal when an emergency call is made.
A telephone exchange appratus according to the present invention comprises an extension interface corresponding to an extension to which an extension telephone terminal is connected, an MF signal source for converting data into MF tone data, an interface connected to a line corresponding to an emergency call MF tone signal, a signal generation means for generating an emergency call data upon inputting a dial signal of emergency call from the extension telephone terminal and for transmitting the generated data to the MF signal source to convert into an emergency call MF tone signal, and a transmission means for sending the emergency call MF tone signal obtained by this signal generation means to the interface to transmit the same to a line corresponding to the emergency call MF tone signal.
By the telephone exchange appratus of the composition, upon the input of a dial signal of emergency call from an extension telephone terminal, an emergency call data is generated, which will be converted into emergency call MF tone signal and sent to the interface, and a appropriate emergency call shall be made to a line corresponding to the emergency call MF tone signal.
A telephone exchange appratus according to the present invention comprises an extension interface corresponding to an extension to which an extension telephone terminal is connected, an MF signal source for converting data into MF tone data, an interface connected to a line corresponding to an emergency call MF tone signal, a line interface connected to a line corresponding to emergency call, a signal generation means for generating an emergency call data upon the input of a dial signal of emergency call from the extension telephone terminal and for transmitting the generated data to the MF signal source to convert into emergency call MF tone signal, and a transmission means for sending the emergency call MF tone signal obtained by this signal generation means to the interface to transmit the same to a line corresponding to the emergency call MF tone signal, or for sending it to the line interface to transmit to the line corresponding to the emergency call.
By the telephone exchange appratus of the composition, upon the input of a dial signal of emergency call from an extension telephone terminal, an emergency call data is generated, which will be converted into emergency call MF tone signal and sent to a line corresponding to the emergency call MF tone signal or to a line corresponding to the emergency call, and an appropriate emergency call shall be made to the line corresponding to the emergency call MF tone signal, or to the line corresponding to the emergency call.
A telephone exchange appratus according to the present invention comprises an extension interface corresponding to an extension to which an extension telephone terminal is connected, an MF signal source for converting data into MF tone data, a line interface connected to a line corresponding to emergency call, a signal generation means for generating an emergency call data upon the input of a dial signal of emergency call from the extension telephone terminal and for transmitting the generated data to the MF signal source to convert into an emergency call MF tone signal, and a transmission means for sending the emergency call MF tone signal obtained by this signal generation means to the line interface to transmit the same to a line connected to this line interface.
By the telephone exchange appratus of the composition, upon the input of a dial signal of emergency call from an extension telephone terminal, an emergency call data is generated, which will be converted into an emergency call MF tone signal and sent from the line corresponding to the emergency call, and an appropriate emergency call shall be made to the line corresponding to the emergency call.
A telephone exchange appratus according to the present invention comprises an extension interface corresponding to an extension to which an extension telephone terminal is connected, a first line interface connected to a line corresponding to emergency call, a second line interface connected to a line not corresponding to the emergency call, an emergency dial determination means for determining, upon the input of a dial data after the capturing operation of the extension, the first line or the second line, from the extension telephone terminal, whether the dial data corresponds to a dial number for emergency call or not, a line capture switching means for releasing an actually captured line and for capturing the first line, when this emergency dial determination means determines that an input corresponding the dial number for emergency call has been made, and a dial data transmission means for transmitting the dial data for emergency to the first line captured by this line capture switching means through the first line interface.
By the telephone exchange appratus of the composition, upon the input of a dial data after the capturing operation of the extension, the first line or the second line, from the extension telephone terminal, it is determined whether the dial data corresponds to a dial number for emergency call or not, and when it is determined that an input corresponding the dial number for emergency call has been made, the actually captured line will be released, the first line shall be captured and the dial data for emergency be transmitted to ensure an appropriate emergency call to the first line.
A telephone exchange appratus according to the present invention comprises an extension interface corresponding to an extension to which an extension telephone terminal is connected, a line corresponding interface to which an emergency call unit is connected, a determination means for determining whether a dial data input from the extension telephone terminal is a data corresponding to a given number, and a transmission means for calling the emergency call unit from the interface when this determination means determines that it is a data corresponding the given number and, for transmitting the identification information of the extension telephone terminal to the emergency call unit through the line corresponding interface when a response signal returns from this emergency call unit.
By the telephone exchange appratus of the composition, when it is determined that a dial data input from an extension telephone terminal is a data corresponding to the given number, the emergency call unit shall be called out and the identification information of the extension telephone terminal be sent to the emergency call when a response signal returns from this emergency call unit to perform an appropriate emergency call processing to the emergency call unit.